Heretofore it has been customary to employ laterally movable gates positioned above the so-called actuating rod to clamp the device in the operating trench so that sufficient axially directed forces can be exerted on the actuating rod to drive it through the ground to the target trench on the opposite side of where the underground pipe or cable is to be installed. The earth above the actuating rod being closer to the normal surface of the ground is softer and is more susceptable to caving in and shifting which misdirects the actuating rod and renders it more difficult to operate.